Tray forming apparatus

ABSTRACT

Individual precut and prescored tray blanks are withdrawn from a stack and fed to an infeed station of the machine, each blank being provided with adhesive while enroute to said infeed station, and each blank being oriented with its end flaps in radially spaced relationship with respect to the axis of rotation of a mandrel which moves upwardly from beneath the blank to engage it at the infeed station and move it upwardly against four fixed corner tab deflecting plows. The inner radial edge of the blank is engaged by a pair of pivotally mounted fingers which fold the inner end flap through 90* as the blank is moved downstream by the mandrel. Projecting portions of these fingers also fold the corner tabs through 90* with respect to the inner end flap, while a pair of resilient leaf spring elements fold the outer end flap at substantially the same time. The outer pair of corner tabs are folded solely by the above mentioned fixed corner tab engaging plows. A pair of opposed side walls have upstream edges for supporting these flap folding elements, and also for supporting fixed side flap folding members so arranged as to engage the side flaps of the blank as it travels between the axially spaced side walls. The continuously moving mandrel then carries the folded tray through substantially 180* of its rotation to set the adhesive prior to arrival at a discharge station, where an eject cylinder carried within the mandrel, punches the tray downwardly so that it drops downwardly onto a take-away conveyor.

United States Patent Lattke [S4] TRAY FORMING APPARATUS [72] Inventor:Horst G. Lattke, Middletown, Conn.

[73] Assignee: Emhart Corporation, Bloomfield,

Conn.

[22] Filed: July 17, 1970 [21] Appl. No.: 55,643

[52] US. Cl ..93/51.l, 93/44.1, 93/53 SD, 93/59 ES, 271/32 [51] Int. Cl..8311) 1/32 [58] Field of Search ..93/51.1,51 R,51 M, 53 SD, 93/44.1

[56] References Cited UNITED STATES PATENTS 2,599,008 6/1952 Palmer..93/51.1 3,138,905 6/1964 Ellinger ..93/51 M 2,135,409 11/1938 Munn etal ..93/51.1 X

Primary Examiner-Bernard Stickney Attorney-McCormick, Paulding & Huber7] ABSTRACT Individual precut and prescored tray blanks are withdrawnfrom a stack and fed to an infeed station of 1 Aug. 15, 1972 themachine, each blank being provided with adhesive while enroute to saidinfeed station, and each blank being oriented with its end flaps inradially spaced relationship with respect to the axis of rotation of amandrel which moves upwardly from beneath the blank to engage it at theinfeed station and move it upwardly against four fixed comer tabdeflecting plows. The inner radial edge of the blank is engaged by apair of pivotally mounted fingers which fold the inner end flap throughas the blank is moved downstream by the mandrel. Projecting portions ofthese fingers also fold the corner tabs through 90 with respect to theinner end flap, while a pair of resilient leaf spring elements fold theouter end flap at substantially the same time. The outer pair of comertabs are folded solely by the above mentioned fixed comer tab engagingplows. A pair of opposed side walls have upstream edges for supportingthese flap folding elements, and also for supporting fixed side flapfolding members so arranged as to engage the side flaps of the blank asit travels between the axially spaced side walls. The continuouslymoving mandrel then carries the folded tray through substantially of itsrotation to set the adhesive prior to arrival at a discharge station,where an eject cylinder carried within the mandrel, punches the traydownwardly so that it drops downwardly onto a take-away conveyor.

19 Claims, 8 Drawing Figures PATENTEI] AUG 15 I972 SHEET 1 OF 5ATTORNEYS PATENTED B 1973 3.683, 755

SHEET 2 OF 5 FIG. 2

FIG. 3

P'A'TENTEDAus 15 I972 SHEET 3 [IF 5 TRAY FORMING APPARATUS BACKGROUND OFTHE INVENTION Machines for forming trays from flat blanks by foldingside and end flaps around a mandrel are old in the art. For example,U.S. Pat. No. 3,080,796 issued to Twitchell et al. in 1963 shows onesuch machine adapted to feed blanks fromthe bottom of a stack to aposition wherein a reciprocating mandrel moves into contact with theblank to force it past resilient flap folding elements which fold theside and end flaps through 90. However, this machine is not adapted tofold blanks which have been provided with strips of adhesive atpredetermined portions. In the Twitchell machine, the blanks are notprovided with corner tabs, but rather have short strips of tape appliedto each of the four comers of the folded blank or tray to hold the sideflaps in position.

U.S. Pat. No. 3,512,459 issued to DiFrank in 1970 shows a machine forfolding blanks which do have corner tabs, and which blanks are providedwith adhesive while enroute to a forming station after having beenwithdrawn from the magazine by a vacuum feed table. Other supportingmeans is provided at the forming station, while the feed table returnsfor another blank, and a reciprocable mandrel engages the blank fromabove so that pivotally mounted flap folding elements may operatesequentially on the blank as it is held at the forming station by themandrel. The side and the end flaps as well as the corner tabs arefolded while the blank is held in a stationary condition, after whichthe mandrel urges the blank, in its folded condition, downwardly into acompression unit where the blank is held in its folded condition untilthe adhesive sets.

In the Twitchell patent the tray must be held together with strips oftape at its four comers, and the machine is not adapted for foldingblanks with corner tabs, which blanks are provided with an adhesive atpreselected portions as they move from a magan'ne to a forming station.In the DiFrank patent the blank does have corner tabs, but the mandrelis moved in a reciprocating discontinuous fashion, and the flap foldingelements themselves must be driven while the blank is held at theforming station with the result that a rather complex mechanism isprovided for forming the resulting tray. One aim of the presentinvention is to provide a machine in which the motion of the mandrel iscontinuous, and which motion is also used to fold the side flaps and endflaps and corner tabs as the blank is fed past movably mounted elementswhich need not be driven as in the machine disclosed in DiFrank. Thisaim of the present invention must be fulfilled in a machine wherein thefolded blank, or tray, is held in a compressed condition long enough toset the adhesive after being so formed The machine disclosed hereinaccomplishes the foregoing aim as well as others to be discussedhereinbelow by providing a mandrel which rotates so as to move the blankbetween pivotally mounted flap elements to form the tray while it ismoving downstream, which mandrel also serves to move the folded traythrough a compression section of the machine so as to set the adhesive,and finally which mandrel includes means for ejecting the formed tray ata discharge station. All of the above functions are accomplished by acontinuously rotating mandrel in the machine to be described.

Machines for continuously moving a blank while its flaps are so foldedare somewhat rare. intermittently operated rotary carriers have beenshown in prior art patents however. For example, U.S. Pat. No. Re214,445 issued toWaters in 1940 shows one such rotary device, and U.S.Pat Nos. 1,808,014 and 1,864,632 both issued to Bergstein in 1931 and1932 respectively-are further examples of such machines. A continuouslyrotating mandrel or carton forming device which is adapted to move. ablank between fixed and movably mounted flap folding, elements is shownin U.S. Pat. No. 2,220,960 issued to Jurgens et al. in 1940. However,the machine disclosed in the Jurgens patent does not show or suggest theabove-mentioned advantages to forming a flat blank which has beensupplied with a quantity of adhesive. For example, J urgens not onlyfails to reveal an adhesive applying station, but the Jurgens patentdoes not disclose adjustably mounted side walls for forming trays ofvarious size, and so designed as to set the adhesive as the tray iscontinuously moved by the mandrel, not only through the infeed stationand through the end flap and side flap forming stations, but alsothrough the compression station of the machine and through the dischargestation. At the discharge station the present machine provides forrejecting the formed tray without interrupting the motion of themandrel.

A further aim of the present invention is to provide an apparatus forforming upwardly open trays from flat precut blanks by a movable mandrelwherein the blank so formed is adapted to be accurately positioned at aninfeed station so as to be engaged by the mandrel with the result thatits end and side flaps are folded on predetermined score lines as theblank is accurately held in position by novel blank retaining means atsaid infeed station. The foregoing object is accomplished in spite ofthe fact that each blank is with drawn from a stack of like blanks, andfed quite rapidly to the infeed station by novel mechanism in the formof a pair of rollers one of which is driven and the other of whichcomprises a back-up roller driven by a blank fed therebetween whichback-up roll is pivotally mounted for oscillatory motion from and to ablank engaging position in cooperation with the means for withdrawingthe lowermost blank from the stack.

SUMMARY OF INVENTION The machine disclosed and claimed hereinaccomplishes the foregoing aims and objects by utilizing a novelmechanism for withdrawing the lowermost blank from a stack of likeblanks, feeding it past an adhesive applying station to an infeedstation where the blank is accurately and firmly held in position byunique side guides prior to being engaged by a rotating mandrel to becontinuously conveyed through the machine to a discharge station. Themandrel moves the blank downstream between inner and outer pairs offixed plows, which plows at least partially deflect the four corner tabscarried by the inner and outer end flaps of the blank. The side flapsare separated from these corner tabs by precut notches, and the innerpair of fixed plows carry pivotally mounted end flap folding fingerswhich are engaged by the blank and pivot through predetermined angulardisplacements so that corner tab folding plows carried on these fingersserve to fold the associated pair of corner tabs through 90 with respectto the inner end flap even as the inner end flap itself is folded bythese fingers. The outer end flap is folded by a pair of resilient leafspring members carried by the outer pair of corner tab folding plows,and the side flaps are subsequently folded by fixed plows comprising apart of the upstream edges of two paralled axially spaced side wallsbetween which the folded blank or tray is continuously moved through asubstantial angle, preferably 180. These side walls are adjustablymounted and serve to hold the tray while the adhesive sets and while thecontinuously rotating mandrel is moving the tray to the dischargestation. At the discharge station an eject cylinder, carried within themandrel, ejects the tray onto a take-away conveyor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of amachine for forming trays from fiat blanks according to the presentinvention. I

FIG. 2 is a plan view of the machine shown in FIG. 1.

FIG. 3 is an end view showing the discharge end of the machine shown inFIGS. 1 and 2.

FIG. 4 is a schematic isometric view showing several successivepositions of a blank as it is acted upon by the mechanism of FIGS. 1through 3 inclusively during the path of movement of said blank throughthe machine.

FIG. 5 is a detailed vertical sectional view through a plane extendingradially through the axis of rotation of the mandrel, and through theblank carried thereby showing in detail the instantaneous configurationof the inner and outer end flap folding elements.

FIG. 6 is a view similar to FIG. 5 but taken at a slightly later instantof time.

FIG. 7 is a vertical sectional view of a portion of the apparatus shownin FIG. 2, being taken on the line 77 of that view, but with portions ofthe machine being omitted for clarity.

FIG. 8 is a plan view of the mechanism shown in FIG. 7.

DETAILED DESCRIPTION Turning now to the drawings in greater detail,FIGS. 1, 2 and 3 show in side elevation, plan and end views respectivelythe overall configuration of the machine described herein and embodyingthe invention set forth in the appended claims. The machine includes anelongated frame comprising left and right-hand vertically extendingfixed side walls 10 and 12 supported upon two pairs of laterally spacedfeet 14 and 16. Intermediate the upper and lower edges of these sidewalls 10 and 12 a pair of longitudinally extending channel shapedsupport members 18 and 20 are provided. These members extend the fulllength of these side walls 10 and 12 as best shown in FIG. 2. A rotaryshaft 22 extends laterally across and between the space between thechannel members 18 and 20, being journaled at each end in a bearingblock supported on the upper flange of each of these channels as shownin FIG. 3 at 24 and 26. The side walls 10 and 12 comprising the fixedframe of the machine are supported in the area below the longitudinallyextending channels 18 and 20 by upstream and downstream end walls 28 and29 respectively. The side walls 10 and 12 are supported in the areaabove the longitudinally extending channels 18 and 20 by a plurality oflaterally extending support rods 30, 30 mounted at each end to the endwalls 10 and 12 respectively.

Still with reference to FIG. 3, and as also shown in FIGS. 1 and 2,several rotary shafts 32, 32 are also provided in the space between thefixed side walls 10 and 12 of the machine frame, and each of theseincludes a left and a right-hand threaded end portion, respectively, forrotatably supporting correspondingly threaded nuts 34, 34, which nuts inturn carry adjustably mounted side walls 36 and 38 arranged in paralledrelationship to the fixed walls 10 and 12 and adapted to be moved towardand away from one another in accurately spaced relationship to thecenter line of the machine simply by rotating the five shafts 32, 32.These shafts 32, 32 are connected to one another by a plurality ofsprockets 40, 40 all of which have entrained thereon a chain 42 whichchain can be driven in one or an opposite direction in response torotation of one of these shafts 32. A hand crank or the like, best shownin FIG. 3 at 44, is provided for adjusting the lateral spacing of thewalls 36 and 38.

The rotary shaft 22 defines the main axis of the machine, and supports arotary device which in the embodiment shown comprises a pair ofgenerally diametrically opposed radially extending arms 50 and 52 whicharms are adapted to rotate in a clockwise direction as viewed in FIG. 1in response to rotation of a chain drive mechanism indicated generallyat 54 from the main drive motor 56 located in the lower portion of themachine. Each of these arms 50 and 52 is adapted to carry an adjustablemandrel, 58 and 60 respectively, the shape of these mandrels being sochosen as to correspond to the dimensions of the bottom of a blank fromwhich a tray is to be formed. Means is provided on each of these arms 50and 52 for ejecting a formed tray generally downwardly at the positionshown for the arm 52 in FIG. 1, and said means comprises an air driveneject cylinder 62 which is shown in FIG. 1 in its extended condition asfor example after discharging a formed tray T at this station so thatthe tray drops downwardly onto a take-away conveyor 66. The ejectcylinder 64 associated with the mandrel 58 at the infeed station of themachine is shown in its retracted position so as to allow a blank B tobe received at said infeed station to be engaged by the mandrel 58 asthe arm 50 rotates said mandrel through the infeed station to lift theblank B through flap folding devices to be described in greater detailhereinbelow, for forming the blank B into a tray T as indicatedschematically in FIG. 4.

Means is provided for feeding blanks to the infeed station of themachine, and as shown in FIG. 1 said means includes a blank magazine,indicated generally at 70, wherein a plurality of these blanks B,B arestacked one above another so as to be sequentially withdrawn from thelower end of the magazine to be fed into the machine from left to rightas viewed in FIG. 1. It will of course be apparent that these blanksmight also be fed to the infeed station through an opening 12A in thefixed frame side wall 12 of the machine, or through a similar opening10A in the opposite side wall 10 without departing from the scope of thepresent invention.

The magazine 70 is of conventional construction and comprises at leastfour corner posts 72, 72 at least three of which are adjustably mountedso as to accommodate blanks of various size, and these blanks arepreferably stored in a slightly inclined position so as to be readilywithdrawn from one side edge before the other to a horizontal positionfor transfer in a horizontal direction to the infeed station of themachine in a manner to be described. The magazine is supported on aninclined upper table portion 74 of a cantilevered portion of the machineframe 76. The cantilevered portion 76 of the machine frame is joined tothe front wall 28 of the machine frame by conventional means and housesthe blank withdrawing means to be described.

Means is provided for withdrawing the lowermost blank B in the stack,and preferably said means comprises a pivotally mounted vacuum cup 80which is adapted to be oscillated between the broken line position shownin FIG. 1 and a blank pick-up position wherein the vacuum cup 80 islocated in engagement with the lowermost blank in the stack. Vacuumcontrol means is provided for selectively connecting the vacuum cup 80to a source of suction or vacuum when the cup reaches the pick-upposition referred to and until said cup is returned from the pickupposition to the broken line position shown. The vacuum cup 80 isconnected to a vacuum pump, indicated generally at 82, by means of aline 84 which line is normally not vented to atmosphere, but which maybe so vented by opening a solenoid valve indicated generally at 86, Alimit switch LS-l is provided on the cantilevered portion 76 of themachine frame for engaging a cam 88 located on a rotating shaft 90continuously driven in one direction by drive means indicated generallyat 92 from the primary drive motor 56 mentioned above. The shaft 90 alsocarries a sprocket for driving a drive chain 94 which rotates a shaft 96associated with the lever arm 98 upon which the vacuum cup 80 ismounted. The shaft 96 carries a crank arm 100 which oscillates in acounterclockwise direction so as to lift the lever arm 98 through apredetermined angular displacement to permit the vacuum cup 80 tosequentially contact the lowermost blank Bin the magazine 70 after whichthe crank arm 100 continues to rotate back to the position shown in saidcounterclockwise direction in order to cyclically move the vacuum cup 80through its limited angular displacement for engaging and pullingdownwardly by gravity the lowermost blank in the stack. When a blank Bhas been so withdrawn from the stack, it occupies a horizontal deliveryposition on a roller 108. The rotary cam 88 then closes limit switchLS-I causing solenoid valve 86 to open and venting the vacuum within thevacuum cup 80 and hence releasing the blank. Means is provided forfeeding the blank from this delivery position to the infeed stationdescribed above, and said means will now be described in detail.

Still with reference to FIG. 1, the rotary cam 88 also acts upon thedepending crank arm 102 of a bellcrank 104 so as to rotate the bellcrank104 in a counterclockwise direction from the position in which it isshown to a blank engaging or active position wherein a backup roller 106operates in conjunction with a continuously driven roller 108 forfeeding a blank from the delivery station between these rollers 106 and108 generally toward the infeed station of the machine. Moreparticularly, when the vacuum cup 80 has withdrawn the lowermost blankfrom the stack and has moved this blank to the delivery position, theleading edge of said blank will be located adjacent the periphery of thecontinuously driven roller 108. This roller 108 is continuously drivenin a clockwise direction by a drive chain 110 which chain 110 iscontinuously driven by an auxillary drive motor 112. However, until thevacuum is released to atmosphere by means of the solenoid valve 86 theblank B will remain at the delivery position, with the result that theoscillatory movement of the bellcrank 104 can be timed in relationshipto the release of vacuum in the cup 80 so that just prior to movement ofthe back-up roller 104 from the solid line position shown to its activeposition, wherein said back-up roller engages the blank B at thedelivery position, the vacuum is released by closing of limit switchLS-l. FIG. 2 shows the continuously driven blank feeding roller 108 ascomprising a plurality of axially spaced blank engaging rolls 108Acarried on a single shaft continuously driven in one direction by theauxillary drive motor 112. A drive chain 114 is entrained on a sprocketassociated with this auxillary motor 112 and with the shaft upon whichthe continuously driven roller 108 is located. This chain 114 alsopasses over a third sprocket 116 associated with a nylon belt conveyor118 which serves to feed the blank downstream from the driven andback-up rollers, 106 and 108 respectively, to the infeed'station, andmore particularly against a fixed stop 120. A pair of fixed guides,132,132 supported from the fixed frame of the machine by brackets126,126. Referring more particularly to FIG. 7, the nylon belt conveyors118,118 are continuously driven in the direction for carrying a blank tothe infeed station and said blank travels between the side guides132,132 each of which guides is adjustably supported on an angle memberconnected to the machine frame by the brackets 126,126. Each guidecomprises a longitudinally extending spring steel member supported atspaced locations from the angle member by screws 124,124 best shown inFIG. 8. In order to prevent the blank B from bouncing against the fixedstops 120,120 these spring steel guides 132,132 are provided within-turned downstream end portions, located slightly upstream of thefixed stops 120,120 and so spaced laterally with respect to one anotheras to forcably deform a short segment of the side edge 122 of a blankfed therebetween against the fixed stops 120,120. As a result of sodeforming the side edges of the blank B, in the manner suggested in FIG.8, the blank is prevented from bouncing back from its position againstthe stops 120,120.

The downstream edge portions of these spring steel guides 132,132 areadapted to be adjusted in a desired position so as to pemiit theoperator of the machine to set them at the desired spacing to assurethat the blank B does not bounce against the stops 120,120 and that theblank is accurately located at the infeed station of the machine priorto being engaged by the mandrel 58 as it passes through the infeedstation and moves the blank through the machine for forming it into atray. Adjusting screws 134,134 are carried by the depending web portionof the angle member I30 of each side guide for this purpose, and theinner end of each screw 134 abuts the spring steel flexible guide 132 asbest shown in FIG. 7 so as to urge the downstream edge portion of theresilient guide 132 into a desired position against the restrainingforce of the screws 124,124 which support the guide 132 as described.

Turning next to a detailed description of the path of movement of theblank from its initial position at the infeed station mentioned above,to its discharge position mentioned briefly hereinabove, one of theplurality of arms, for example the arm 50, is adapted to carry arectangular mandrel 58, which engages the underside of the blank B tocarry it upwardly in a downstream direction through substantially 180 ofangular rotation prior to discharging the tray T downwardly as a resultof actuation of an eject cylinder 62 provided for this purpose in themandrel. The blank B will have been preglued, or provided with apredetermined quantity of adhesive, in traveling to the infeed stationby a conventional applicator device A best shown in FIG. 4. As will beapparent from FIG. 4, the blank B is formed into a tray T by mechanismsto be described, and this forming operation is accomplished through arelatively small angular displacement of the blank in its 180 ofrotation in the machine. It is an important feature of the presentinvention that during a major portion of this angular travel the traywill have been formed into its final shape, and as a result of havingbeen preglued, the tray is held in this configuration for a significantportion of the machine cycle so as to set the adhesive while the tray isbeing conveyed between the adjustable side walls 36 and 38. A pair ofarcuate inner radial wall segments 37 and 39 are shown in FIG. 1, forholding the inner end flap of the blank against the inner side of themandrel 58. While an adjustable outer radial wall might be provided foraccomplishing the same purpose with respect to the outer end flap it hasbeen found to be unnecessary when the adjustable side walls 36 and 38are properly positioned. It will also be apparent that other means mightbe provided for holding the outer end flap in position against the outerface of the mandrel 58 during this compression portion of the travel ofthe tray, indicated generally by the arrows 150,150 in FIG. 4. Forexample, weighted belts or the like might be provided between fixedlocations on the machine frame for holding the outer end flaps inposition during this portion of the machines cycle. Still with referenceto FIG. 4 it will be seen that the mandrel 58 is provided with prongs orneedles 59,59 which are adapted to engage the cardboard blank so as tohold the blank in accurately indexed position on the mandrel during itstravel from the infeed station to the folding station of the machine. Itshould also be mentioned that other variations of the mandrel 58 mightbe conceived within the scope of the present invention. For example, aslug of articles to be packaged might be prepositioned at the infeedstation on a rotating arm of the type shown at 50 so that upwardmovement of the arm 50 causes these articles themselves to act as amandrel for forming the blank B into a tray, and for providing aconvenient manner for forming the tray simultaneously with the fillingof the tray with a slug or group of articles to be packaged.

Each of the blanks B,B can be seen from FIG. 4 to include side flaps, Cand D, as well as outer and inner end flaps, E and F respectively, allof which are connected to a bottom panel of the blank along prescoredfold lines as indicated by the broken lines in FIG. 4. In the type ofblank with which the present machine is concerned, each blank furtherincludes comer tabs G, G and H, H associated with the inner and outerend flaps, F and E respectively, and connected to these end flaps alongprescored fold lines but separated from the side flaps C and D by precutnotches as is conventional practice in the art. As described above, andas suggested in FIG. 1 the flat blank B is fed to an infeed stationdefined by the fixed stop and is-held in accurately indexed relationshipto the stop as a result of the novel side guides with their inturnedtrailing edge portions for deforming the leading edge portion of theblank slightly so as to hold the blank in an accurate position withrespect to the axis of rotation defined by the shaft 22. As so disposedthe blank is oriented in a plane which is horizontal and radiallydisposed with respect to the axis of rotation of the mandrel 58. Theside flaps C and D can be seen to also be disposed radially, and the endflaps oriented in spaced radial relationship to one another. The endflap F will be referred to herein as the inner radial flap and the endflap B will be referred to as the outer one. With further reference toFIG. 1, the adjustable side walls 36 and 38 can be seen to have upstreamedges 36A and 38A which terminate downstream of the infeed stationitself so that the blank B will not engage the side walls as it is fedto the infeed station. As said blank is moved downstream of thisposition, in an upward direction, by the rotating mandrel 58, it will beacted upon by flap folding devices carried by these side walls.

The said upstream edges of these left and right hand side walls carryinner and outer radial pairs of fixed plows, best shown in FIGS. 5 and 6at 152 and 154 respectively. More particularly, each of the side walls36 and 38 carries a pair of fixed inner plows 152,152 located in thepath of movement of the inner corner tabs G,G of the blank and anadjustably mounted pair of outer plows 154,154 associated with the outercomer tabs H,H of the blank so as to engage these comer tabs and deflectthem as the blank is moved downstream beyond the infeed station by themandrel 58. The adjustably mounted outer pair of plows 154,154 permitcarton blanks of various size to be readily accomodated. Thus, the blankB, as it is conveyed upwardly on the mandrel 58, first engages thesefour comer tabs deflecting plows which deflect these corner tabs atleast slightly prior to engaging of the blank with other flap foldingdevices to be described.

The inner and outer pairs of flap folding devices differ from oneanother, and FIGS. 5 and 6 show these devices in detail, as well asindicate their manner of operation. The inner means for folding theinner end flap F comprises a pair of pivotally mounted flap foldingfingers which are mounted on the comer tab deflecting plows 152 and 152respectively. Each finger includes a projecting portion normallyoriented in the path of movement of the blank so as to be engaged by theblank generally adjacent the fold line associated with the end flap F tocause this finger to pivot in a clockwise direction as viewed in FIGS. 5and 6 from the position shown in FIG. 5 to the position shown in FIG. 6as the blank and associated mandrel move through the successivepositions shown in these views. Each finger also includes a corner tabdeflecting plow 162 carried on a depending portion of the finger whichplow is adapted to engage the corner tab so as to deflect it downwardly,after having been engaged by the fixed plow 152, so as to further bendsaid comer tab G about its fold line. Spring biasing means 164 isprovided for urg'ng the pivoted finger toward the position shown in FIG.during this preliminary engagement period. As the blank B moves form theFIG. 5 position to the FIG. 6 position the finger will pivot in aclockwise direction as mentioned above, the spring 164 will extendslightly allowing this predetermined angular displacement, with theresult that the plow 162 provided for this purpose on the finger causesthe corner tab G to assume a position oriented at 90 with respect to theend flap F itself. At the same time the depending portion of finger isso oriented as to urge the end flap F against the inner surface of themandrel 50. As can be seen from FIG. 6 the finger will ultimately alignitself with the arcuate surface 37 on the adjustable side wall 36thereby holding the end flap F positively in this position as the foldedtray is conveyed through the compression section of the machine in themanner described above. Still with reference to FIGS. 5 and 6, thecorner tab engaging plows 152,152 associated with the pivoted fingers160,160 are arranged outboard of these fingers so as to engage thecorner tabs and fold them slightly prior to the further folding throughsubstantially 90 accomplished by the plows 162,162. The plows 162,162provided on the depending lower portions of the fingers 160, 160 arealso offset axially outwardly with respect to these fingers to allow thefolded blank to pass therebetween to the compression section.

Considering next the folding of the outer end flap E associated with theradially outer end of the blank, FIGS. 5 and 6 show resilient leafspring members 170, 170 mounted to the outer pair of corner tabdeflecting plows 154,154 respectively. Each of these leaf spring members170 is of generally L-shape, and has a projecting or cantileveredportion which is normally oriented in the path of movement of the endflap E as the blank is moved through the successive positions shown inFIGS. 5 and 6 so that the end flap E of the blank engages theseresilient leaf springs to fold the end flap E through substantially 90as the blank is moved downstream by the mandrel. Each of these leafspring members 170 is pivotally mounted at its lower end, cantileverfashion, on a fixed post 174 and may include a back-up spring 176 whichis similarly arranged should the additional restoring force be requiredin folding particularly stiff blanks. A stop member 172 is provided forengaging an outer end portion 178 of each of these springs 170,170 so asto hold the leaf spring member in its normal position in the path ofmovement of the blank as mentioned above. As a result of locating thesesprings 170, 170 on the adjustably mounted outer pair of plows 154,154respectively, it will be apparent that the machine can be convenientlyand quickly set up to accomodate blanks of various sizes.

Once the inner and outer end flaps, F and E respectively, of the blankhave been folded through substantially 90, and the corner tabs have beenturned inwardly toward one another in the manner described above withreference to the inner corner tabs, and as a result of the fixed plows154,154 associated with the outer corner tabs H,H, the side flaps C andD are engaged by fixed plows 180, 180 associated with the upstream edges38A and 36A of the adjustable side walls 36 and 38 respectively forfolding the side flaps C and D downwardly and causing the adhesivecoated portions of the corner tabs and/or side flaps to engage oneanother. Further rotation of the mandrel 58, and the associated tray T,between the side walls 36 and 38 serves to set the adhesive so that whenthe tray and mandrel arrive at the discharge station, indicatedgenerally at 60 for the mandrel in FIG. 1, a limit switch LS-2 is closedby engagement with a fixed cam surface 180, defined in the machineframe, opening a solenoid valve (not shown) for extending the ejectcylinder 62 and thereby discharging the tray T from the mandrel allowingit to drop downwardly onto the take-away conveyor 66.

I claim:

1. Apparatus for forming trays from initially flat rectangular blankswhich include side flaps and end flaps connected to a bottom panel onprescored fold lines, and comer tabs connected to the end flaps andseparated from the side flaps by precut notches; said apparatuscomprising a magazine for storing a plurality of such blanks, means forwithdrawing the blanks individually and feeding each to an infeedstation, means for applying adhesive to selected portions of the blankas it is fed to said infeed station, at least one blank engaging mandrelrotatably supported on an axis in the machine for arcuate movementthrough the infeed station to engage a blank oriented in a plane whichis radially oriented with its side flaps radially disposed and its endflaps oriented in spaced radial relationship to one another, said blankbeing moved arcuately in a downstream direction by said mandrel, axiallyspaced walls located on either side of the path of movement of saidmandrel and having upstream edges spaced downstream from said infeedstation, inner and outer pairs of fixed plows mounted to said side wallsand projecting beyond said upstream edges thereof to engage the cornertabs and deflect them as the blank is moved downstream beyond the infeedstation, non-powered means for subsequently folding said end flaps andfor further folding said corner tabs simultaneously therewith, and meansfor folding said side flaps so that said upstream edges of said sidewalls hold said side flaps against the corner tabs which are in turnheld in place by said mandrel to set the adhesive while the tray ismoved arcuately between said side walls.

2. The combination set forth in claim 1 further characterized by meansfor. adjusting said side walls toward and away from one another toaccommodate carton blanks of various size.

3. The combination set forth in claim 1 further characterized in thatsaid non-powered means for folding said end flaps comprises at least onepair of pivotally mounted flap folding fingers each of which fingers hasa portion for engaging said one end flap to fold it back throughsubstantially as the blank is moved downstream by said mandrel, saidfingers being mounted for limited pivotal movement in response topassage of the mandrel and an associated blank, said pivotal movement ofsaid pair of fingers occurring about a common axis spaced radially awayfrom the fold line associated with said one end flap.

4. The combination set forth in claim 3 further characterized in thatsaid flap folding fingers further include projecting plows for engagingsaid partially deflected comer tabs to urge them into a substantially 90orientation with respect to their associated end flaps at the same timeduring which said fingers are folding said end flaps throughsubstantially 90, and a fixed guide rail of arcuate contour associatedwith each side wall for holding said end flap in its folded position assaid mandrel moves the blank downstream.

5. The combination set forth in claim 3 further characterized in thateach of said flap folding fingers is pivotally mounted to one of saidcorner tab deflecting plows, each of said fingers having a projectingportion which is normally oriented in the path of movement of said blankand which is engaged by the blank adjacent said fold line associatedwith said one end flap to cause said finger to pivot through apredetermined angular displacement as said mandrel and its associatedblank move therepast.

6. The combination set forth in claim 5 further characterized that eachof said fingers further includes a projecting plow portion locatedopposite said projecting portion with respect to said pivot axis, whichplow portion is offset axially with respect to said end flap engagingprojecting portion for engaging one of said partially deflected comertabs to urge it into a substantially 90 orientation with respect to itsassociated end flap in response to said predetermined angulardisplacement of said finger.

7. The combination set forth in claim 6 further characterized by biasingmeans for urging each pivoted finger toward said normal position forreturning said finger to said normal position following the passage ofsaid mandrel and an associated blank.

8. The combination set forth in claim 1 further characterized in thatsaid means for folding said end flaps comprises at least one pair ofresilient leaf spring members mounted to one pair of corner tabdeflecting plows, each of said leaf spring members having a projectingportion which is normally oriented in the path of movement of one ofsaid end flaps to be engaged thereby and to fold said end flap throughsubstantially 90 as the blank is moved downstream by said mandrel, saidspring members being flexed slightly in response to passage of themandrel and an associated blank so as to resiliently return to theirnormal orientations following the passage of said mandrel and blank.

9. The combination set forth in claim 8 further characterized in thatsaid means for folding said end flaps further comprises a pair ofpivotally mounted flap folding fingers carried by the other pair ofcomer tab deflecting plows for engaging the other one of said end flapsand folding it back through substantially 90 as the blank is moveddownstream by said mandrel, said fingers being mounted for limitedpivotal movement in response to passage of the mandrel and an associatedblank about a common axis spaced radially away from the fold lineassociated with said one end flap.

10. The combination set forth in claim 9 further characterized in thatsaid flap folding fingers further include projecting plows for engagingsaid partially deflected comer tabs to urge them into a substantially 90orientation with respect to their associated end flap at the same timeduring which said fingers are folding said end flaps throughsubstantially 90, and a fixed guide rail of arcuate contour associatedwith each side wall for holding said end flap in its folded position assaid mandrel moves the blank downstream.

11. The combination set forth in claim 9 further characterized in thateach of said flap folding fingers has a projecting portion which isnormally oriented in the path of movement of said blank and which isengaged by the blank adjacent said fold line associated with said oneend flap to cause said finger to pivot through a predetermined angulardisplacement as said mandrel and its associated blank move therepast.

12. The combination set forth in claim 11 further characterized in thateach of said fingers further includes a projecting plow portion locatedopposite said projecting portion with respect to said pivot axis, whichplow portion is offset axially with respect to said end flap engagingprojecting portion for engaging one of said partially deflected comertab to urge it into a substantially orientation with respect to itsassociated end flap in response to said predetermined angulardisplacement of said finger.

13. The combination set forth in claim 12 further characterized bybiasing means for urging each pivoted finger toward said normal positionfor returning said finger to said normal position following the passageof said mandrel and an associated blank.

14. The combination set forth in claim 9 further characterized by meansresponsive to the arrival of said mandrel and folded blank at adischarge station which is angularly spaced from said infeed station forejecting the folded blank, said means including an eject cylindercarried by said mandrel.

15. The combination set forth in claim 14 wherein said eject meansfurther includes a limit switch so arranged as to be tripped by arrivalof said mandrel at said discharge station, and a valve located in a lineconnecting said eject cylinder to a source of fluid under pressure, saidvalve being operable in response to tripping of limit switch to actuatesaid cylinder at said discharge station as aforesaid.

16'. The combination set forth in claim 9 wherein said means forwithdrawing the blanks from said magazine comprises a vacuum cuppivotally mounted for limited angular movement from and to a blankpick-up position in engagement with the endmost case, conveyor means formoving the blank from a delivery position to which said vacuum cup hasmoved the blank toward said infeed station.

17. The combination set forth in claim 16 wherein said conveyor meansincludes a continuously driven roller which engages a leading edgeportion of the blank when said blank has been so withdrawn by saidvacuum cup, vacuum control means for selectively connecting said cup toa source of vacuum when said cup reaches said pick-up position and forventing said cup to atmosphere when the blank has reached said deliveryposition.

18. The combination set forth in claim 17 wherein said conveyor meansfurther includes a back-up roller for said continuously driven roller, acrank arm pivotally supported in co-axial relationship with said drivenroller and defining a movable axis for said backup roller, cam means forcyclically oscillating said crank arm between a blank engaging positionwherein said back-up roller cooperates with said driven roller to feed ablank therebetween and an inactive position wherein said back-up rollermoves in the downstream direction out of the path of movement of a blankbeing moved into said delivery position and onto said driven roller.

to move it upwardly through 1180, and said eject cylinder serving toeject the folded blank downwardly at said discharge station, and a takeaway conveyor for receiving the downwardly discharged folded blank ortray.

mg UNITED STATES PATENT OFFiCE QERTIFICATE OF (IQRRECTIQN Patent NO.3,683,755 Deted August 15,1972

Inventor-(3) HO I'St G, Lattke It is certified that error appears in the above-i'dentiied 'patent'- ,and that said Letters Patent are herebycorrected as shown below:

Col. 1, line 61, after "flap'tineert o1-qin v .1 Col. 3, line 9,"paralle dt' shoul d be '-para11e1e d- I Col. 4, line 13, 'parelled"ehouId be --pe1" a11e1ed C01. 6, line 48, "forcably" sho1ild be i-forc'eably- -el C01. 8', line 46, "ac c'omo dated" sboul dbe---acc0mm0dated*.

.Col. 9, line 7, ,"fofm" should be -from--. C01. 9, line 59,"accomodate" ebould I be --accommodate---.

Signed and seeled this 8th day of May 1973;

it (SEAL) ttest: v EDWAQD bLFJETCHERJP-u ROBERT GOTTSCHALK.

Attesting f oer Commissioner of Patents

1. Apparatus for forming trays from initially flat rectangular blankswhich include side flaps and end flaps connected to a bottom panel onprescored fold lines, and corner tabs connected to the end flaps andseparated from the side flaps by precut notches; said apparatuscomprising a magazine for storing a plurality of such blanks, means forwithdrawing the blanks individually and feeding each to an infeedstation, means for applying adhesive to selected portions of the blankas it is fed to said infeed station, at least one blank engaging mandrelrotatably supported on an axis in the machine for arcuate movementthrough the infeed station to engage a blank oriented in a plane whichis radially oriented with its side flaps radially disposed and its endflaps oriented in spaced radial relationship to one another, said blankbeing moved arcuately in a downstream direction by said mandrel, axiallyspaced walls located on either side of the path of movement of saidmandrel and having upstream edges spaced downstream from said infeedstation, inner and outer pairs of fixed plows mounted to said side wallsand projecting beyond said upstream edges thereof to engage the cornertabs and deflect them as the blank is moved downstream beyond the infeedstation, non-powered means for subsequently folding said end flaps andfor further folding said corner tabs simultaneously therewith, and meansfor folding said side flaps so that said upstream edges of said sidewalls hold said side flaps against the corner tabs which are in turnheld in place by said mandrel to set the adhesive while the tray ismoved arcuately between said side walls.
 2. The combination set forth inclaim 1 further characterized by means for adjusting said side wallstoward and away from one another to accommodate carton blanks of varioussize.
 3. The combination set forth in claim 1 further characterized inthat said non-powered means for folding said end flaps comprises atleast one pair of pivotally mounted flap folding fingers each of whichfingers has a portion for engaging said one end flap to fold it backthrough substantially 90* as the blank is moved downstream by saidmandrel, said fingers being mounted for limited pivotal movement inresponse to passage of the mandrel and an associated blank, said pivotalmovement of said pair of fingers occurring about a common axis spacedradially away from the fold line associated with said one end flap. 4.The combination set forth in claim 3 further characterized in that saidflap folding fingers further include projecting plows for engaging saidpartially deflected corner tabs to urge them into a substantially 90*orientation with respect to their associated end flaps at the same timeduring which said fingers are folding said end flaps throughsubstantially 90*, and a fixed guide rail of arcuate contour associatedwith each side wall for holding said end flap in its folded position assaid mandrel moves the blank downstream.
 5. The combination set forth inclaim 3 further characterized in that each of said flap folding fingersis pivotally mounted to one of said corner tab deflecting plows, each ofsaid fingers having a projecting portion which is normally oriented inthe path of movement of said blank and which is engaged by the blankadjacent said fold line associated with said one end flap to cause saidfinger to pivot through a predetermined angular displacement as saidmandrel and its associated blank move therepast.
 6. The combination setforth in claim 5 further characterized that each of said fingers furtherincludes a projecting plow portion located opposite said projectingportion with respect to said pivot axis, which plow portion is offsetaxially with respect to said end flap engaging projecting portion forengaging one of said partially deflected corner tabs to urge it into asubstantially 90* orientation with respect to its associated end flap inresponse to said predetermined angular displacement of said finger. 7.The combination set forth in claim 6 further characterized by biasingmeans for urging each pivoted finger toward said normal position forreturning said finger to said normal position following the passage ofsaid mandrel and an associated blank.
 8. The combination set forth inclaim 1 further characterized in that said means for folding said endflaps comprises at least one pair of resilient leaf spring membersmounted to one pair of corner tab deflecting plows, each of said leafspring members having a projecting portion which is normally oriented inthe path of movement of one of said end flaps to be engaged thereby andto fold said end flap through substantially 90* as the blank is moveddownstream by said mandrel, said spring members being flexed slightly inresponse to passage of the mandrel and an associated blank so as toresiliently return to their normal orientations following the passage ofsaid mandrel and blank.
 9. The combination set forth in claim 8 furthercharacterized in that said means for folding said end flaps furthercomprises a pair of pivotally mounted flap folding fingers carried bythe other pair of corner tab deflecting plows for engaging the other oneof said end flaps and folding it back through substantially 90* as theblank is moved downstream by said mandrel, said fingers being mountedfor limited pivotal movement in response to passage of the mandrel andan associated blank about a common axis spaced radially away from thefold line associated with said one end flap.
 10. The combination setforth in claim 9 further characterized in that said flap folding fingersfurther include projecting plows for engaging said partially deflectedcorner tabs to urge them into a substantially 90* orientation withrespect to their associated end flap at the same time during which saidfingers are folding said end flaps through substantially 90*, and afixed guide rail of arcuate contour associated with each side wall forholding said end flap in its folded position as said mandrel moves theblank downstream.
 11. The combination set forth in claim 9 furthercharacterized in that each of said flap folding fingers has a projectingportion which is normalLy oriented in the path of movement of said blankand which is engaged by the blank adjacent said fold line associatedwith said one end flap to cause said finger to pivot through apredetermined angular displacement as said mandrel and its associatedblank move therepast.
 12. The combination set forth in claim 11 furthercharacterized in that each of said fingers further includes a projectingplow portion located opposite said projecting portion with respect tosaid pivot axis, which plow portion is offset axially with respect tosaid end flap engaging projecting portion for engaging one of saidpartially deflected corner tab to urge it into a substantially 90*orientation with respect to its associated end flap in response to saidpredetermined angular displacement of said finger.
 13. The combinationset forth in claim 12 further characterized by biasing means for urgingeach pivoted finger toward said normal position for returning saidfinger to said normal position following the passage of said mandrel andan associated blank.
 14. The combination set forth in claim 9 furthercharacterized by means responsive to the arrival of said mandrel andfolded blank at a discharge station which is angularly spaced from saidinfeed station for ejecting the folded blank, said means including aneject cylinder carried by said mandrel.
 15. The combination set forth inclaim 14 wherein said eject means further includes a limit switch soarranged as to be tripped by arrival of said mandrel at said dischargestation, and a valve located in a line connecting said eject cylinder toa source of fluid under pressure, said valve being operable in responseto tripping of limit switch to actuate said cylinder at said dischargestation as aforesaid.
 16. The combination set forth in claim 9 whereinsaid means for withdrawing the blanks from said magazine comprises avacuum cup pivotally mounted for limited angular movement from and to ablank pick-up position in engagement with the endmost case, conveyormeans for moving the blank from a delivery position to which said vacuumcup has moved the blank toward said infeed station.
 17. The combinationset forth in claim 16 wherein said conveyor means includes acontinuously driven roller which engages a leading edge portion of theblank when said blank has been so withdrawn by said vacuum cup, vacuumcontrol means for selectively connecting said cup to a source of vacuumwhen said cup reaches said pick-up position and for venting said cup toatmosphere when the blank has reached said delivery position.
 18. Thecombination set forth in claim 17 wherein said conveyor means furtherincludes a back-up roller for said continuously driven roller, a crankarm pivotally supported in co-axial relationship with said driven rollerand defining a movable axis for said back-up roller, cam means forcyclically oscillating said crank arm between a blank engaging positionwherein said back-up roller cooperates with said driven roller to feed ablank therebetween and an inactive position wherein said back-up rollermoves in the downstream direction out of the path of movement of a blankbeing moved into said delivery position and onto said driven roller. 19.The combination set forth in claim 14 wherein said infeed station andsaid discharge station are oriented 180* apart with respect to the axisof rotation of said mandrel, said blank being conveyed generallyhorizontally into a horizontal position at said infeed station and saidmandrel engaging said blank from below to move it upwardly through 180*,and said eject cylinder serving to eject the folded blank downwardly atsaid discharge station, and a take away conveyor for receiving thedownwardly discharged folded blank or tray.